


Matter of Time

by Mystical_Light6



Category: Supernatural
Genre: Demon Castiel, Demon Dean Winchester, Horror, M/M, Purgatory, Supernatural Elements, Torture, Transformation
Language: English
Status: Completed
Published: 2013-01-23
Updated: 2014-02-08
Packaged: 2017-11-26 13:44:31
Rating: Teen And Up Audiences
Warnings: Graphic Depictions Of Violence, No Archive Warnings Apply
Chapters: 7
Words: 9,940
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/651113
Author URL: https://archiveofourown.org/users/Mystical_Light6/pseuds/Mystical_Light6
Summary: <blockquote class="userstuff">
              <p>Purgatory AU There would only be one way to truly keep Dean safe in Purgatory and Castiel let the demon out of the box. TW for torture. SLASH</p>
            </blockquote>





	1. Lost

**Author's Note:**

> Disclaimer: I do not own Supernatural
> 
> Prompt from purgatory_spn on lj: Dean + Purgatory = Demon!Dean
> 
> Speaking of demonic Dean, let's say that while he was in Hell Dean started the process of transforming into a demon. Cas halted that process/cleansed that side of him when he pulled Dean out. But all Cas could do was cover it up - part of Dean's soul was still permanently something other than human. Enter Purgatory, a place built to hold monstrous souls. Dean goes native to survive and sort of reverts back to how he acted in Hell, right up to the back eyes (or white eyes :3).  
> Cas can be present or not. If he is, I'd like him to not be as bothered by this as a human would be. I love the idea of the angels having their own alien morality - plus, he's crazy.  
> Maybe Sam rescues him at some point and they have to deal with this new (old?) side of Dean.

It was like an itch he couldn't quite scratch in the beginning. The monsters, they would all just come at him, full force and he'd take them all down with Cas' assistance. Slashing and cutting. Using a gun while he still had a few bullets left. He was, after all, only human. Fragile. Then, when the days were done (or whatever counted as a day) they would sit in a safe place and Dean would notice Castiel staring at him worriedly and start muttering to himself. Dean knew it wasn't normal but he let it slide on account of Cas' crazy sometimes making a surprise appearance. Day after day, hour after hour, Dean and Cas would work tirelessly on "ganking" some monsters and then try to find a way out of this nocturnal craphole universe.

Until one day.

On one day when a little bitch beast got a little too close and wasn't fast enough in their escape. Dean had her pinned down beneath him when suddenly he felt a smooth, cool blade placed reverently into his hand.

"Go ahead," Castiel whispered hotly into his ear and Dean smirked.

"Looks like it's not your lucky day," Dean said to the creature before he began.

Dean hummed under his breath as he touched the knife against her exposed neck in a curved line down to her navel. She hissed in pain and belatedly Dean realized it was a silver knife. _Beautiful._ He knew Castiel was still watching him and he wanted to give the angel a good show. The second time he traced the knife against her stomach in a straight line drawing her blood and the bitch screamed. Dean sighed in ecstasy and continued to hum as he meticulously continued to carve.

Dean knew he should've been more upset by his actions but, looking back at the writhing body - no, Dean felt _good. Strong. Better._

Castiel watched him from a distance and Dean, covered in blood, turned and gave the angel a smirk of satisfaction.

* * *

The first time Dean used telekinesis was a bit of a surprise but he rolled with it. After all, he'd never felt _that_ sort of power before. It was... _intoxicating_. When his eyes sought out Castiel, the angel frowned while studying his face, made some kind of a decision, and vanished.

"Thanks a lot Cas," he said to empty air.

Something came up behind Dean's back and on instinct he clenched his hand into a fist. He began to hear choking. He could get used to this.

* * *

Castiel wasn't gone for long. When he reappeared, Dean was busily sharpening and cleaning one of his two remaining blades.

"Where'd you go?"

Castiel flinched from the screeching noise but then began to speak. "Dean, we need to talk."

"So then talk, _angel_."

_schwick schwick_

"When we arrived in Purgatory I was unsure of how the world might affect you. You being human after all."

"Mhmm."

_schwick schwick_

"I see now that, as time goes by, there is something different. About you."

Dean stood up and idly flipped the blade in his hand. Blade to handle to blade to handle. "And what's so different about me?"

"Your ruthlessness. Your savagery. Your use of telekinesis. Torturing. Mutilating – the list goes on and on. Dean, none of this is you. None of this is the true man you were."

Keyword, were. "So then tell me Cas," Dean said, getting all up into Castiel's personal space for once, "what does all of _this_ mean?"

Castiel walked past Dean and began to speak. "It began years ago, when I first raised you from hell."

"Yeah, and?"

Castiel sighed. "We were almost too late in reaching you and as such, the state of your soul, it was already almost to the point of becoming fully demonic. Irreversibly."

"Go on."

"My brethren and I had a short discussion and decided on suppressing that part of you in order for you to return to earth and act as the Righteous Man we needed. We buried the demonic part of you very deep into your subconscious in the hope you would not turn against the important task we wanted you to do."

Dean definitely didn't miss the use of the word 'we' in that statement.

"Being in purgatory this long has stripped that block within you and..."

"Being so righteous yourself, why didn't you try to stop it?"

"What?"

"Well Cas," Dean said coming very close into the angel's space again, "you could've just stopped demon me from coming out again and you didn't. Why?"

Castiel looked at Dean's lips and swallowed. "Strategy. If I disappeared for a long period of time, physically or mentally, I did not believe that you would be able to defend yourself from attack. When your eyes first went black I thought..."

"I have black eyes?"

"Yes."

"And…are they black right now?"

When Castiel didn't answer fast enough, Dean ripped the sharpened blade from off his belt and held it against the angel's neck.

"Cas?"

"Yes."

Well this was a revelation. Dean knew that he should on some level be upset about it. This was after all one of his worst fears come to life. But... oh, that _power_. Now he understood why Sam had hidden his addiction to demon blood from him. He was foolish to give it up. Dean let go of Cas and returned to his seat.

"We've still gotta find a way out of here," he said gruffly. He put away the first blade and removed his second, beginning to clean and polish that one as well.

"Ideas?"

* * *

The first night after Dean and Cas got out of purgatory and Cas had disappeared to who knows where was the first night Sam noticed something off about his brother. Like at dinner, he'd asked for no salt on his fries which wasn't exactly weird but just a little…off. And when they'd gotten back to his place, Dean had avoided stepping on the rug and asked Sam where he'd put the salt lines. Sam didn't know exactly what had happened in Purgatory but he knew he'd get the story someday, just after Dean readjusted.

It was just a matter of time.


	2. Redeemed

**Notes for the Chapter:**

> Disclaimer: I do not own Supernatural. This is merely being done for amusement and nothing monetary.
> 
> Let's just say that Purgatory...changes people and you can't come out of there totally unaffected.

He was sitting in the last pew of an old cathedral, his hands folded in front of him as he said his final prayer when there was suddenly a clattering noise that distracted him.

"Oh, I thought there was no one here. I'm sorry if I interrupted you."

He looked up and a young priest, smiling and carrying a big box of hymnals was walking up the center aisle laying the books down at the ends of the pews as he went.

"I suppose I forgot to lock the doors after holding mass this morning. We normally don't allow people within unless there's someone available to keep an eye on the building and…"

When the priest looked again, the mysterious man in the tan coat was gone and the priest could swear he heard the echoing sound of flapping wings in his wake.

* * *

_3 Months Earlier, Purgatory Time_

"Move! Move! Move! Move! **MOVE!** "

The giant ( _a fucking giant_ ) roared as it came running after them. Castiel had unfortunately roused the beast from its slumber, believing it to be a rock they could rest on for a short while since they'd been chased by a rather large colony of arachne earlier in the morning. A big mistake on his part.

"Cas, there's a cave up ahead! I can see it!" Dean shouted while turning back to the lagging angel, allowing the pale sunlight to bounce off of his currently ebony black eyes.

Castiel and Dean both ran through the carved out entrance on the side of a mountain whose uppermost peak reached as high as the clouds. The cave turned out to be smaller lengthwise than they'd hoped but, when they reached the farthest wall, they stopped. As one they turned and the giant stood at the entrance for a moment before stalking away.

"You think it's gone?" Dean asked between gasps of breath.

As Castiel began to shrug, a loud creaking noise filled their ears. The pale, foggy light coming into the cave was diminishing as something bigger blocked it out. And then they heard the grunting. The giant was literally pushing a large boulder up against the entrance, _trapping them inside with absolutely no other means of escape!_

"Son of a bitch!" Dean shouted, running forward as the rock slid totally into place, bathing them in darkness.

Castiel remained where he stood, watching as Dean kicked, punched and attempted to telekinetically move the rock but it was just too big for him to move by himself.

"Little help here, angel," Dean snarled.

Castiel walked up to the rock and attempted to push but, well, he'd been keeping a little secret from Dean for the last few days. He gave it a good show but... "I am sorry Dean but I cannot move the boulder."

"You're a - you're a fucking angel of the Lord damn it! Why not?"

"I'm sorry Dean," Castiel said again, exhausted as he sat down on the ground, leaning his back against the stone.

A minute later, Dean followed suit and clapped Castiel on the knee saying, "S'all right, Cas. We'll figure something out."

* * *

Castiel awoke some time after dozing to find Dean sharpening one of his knives again with a good rock he'd found on the ground.

"You fell asleep over an hour ago," Dean said not turning to look at him, "why?"

Castiel rubbed at his itchy, growing beard before answering. "Purgatory is a cage for creatures, Dean. I am not...human as you are. Sometimes I'll have my grace. Other days..."

"You're saying you're outta mojo?"

"For now. It comes and it goes. I thought it pertinent not to mention..."

Dean 'hmmed' as he continued working on his knives. "So we'll have to wait then until your power builds back up again, huh?"

"I suppose...are you angry?"

Dean side eyed him and Castiel was still unused to the unusual look of the black pools of Dean's eyes. He'd liked the bright green much better.

After some time and being so low on energy, Castiel dozed off again as a human might've but he shouldn't have let his guard down and for one very important reason: Dean Winchester had grown bored. When the angel awakened, he was pinned down to the cave floor while Dean was methodically running the point of his knife against any area of Castiel's exposed skin, watching a pool of blood begin to form and then heal. Form and then heal. When finally realizing that the angel was awake, Dean sat up and rolled up his own sleeve.

"Dean," Castiel asked apprehensively, "what are you doing?"

"Experimenting. Hold still."

Castiel, still weak, could only watch in confusion as Dean dragged the knife against the palm of his hand and then plunged the blade deeply along Castiel's forearm, eliciting a surprised scream. When the blood was beginning to pool, Dean put his hand against Castiel's arm, allowing his demonic blood to seep into Castiel's own body. The effect was instantaneous. Castiel's eyes widened as he felt inescapable cold seep into his vessel's body and further into his true form. Dazed, Castiel stared up at the cave ceiling until the feeling faded away. It didn't disappear completely, the feeling, but it just sort of…echoed weakly. It wrapped itself around him like an icy blanket.

"What was that like?" Dean asked, sitting back.

Rising up and rubbing his hand against the wound, Castiel said the first word that came into his head.

"Frigid."

Castiel looked deeply into Dean's eyes. Despite the blank black pools that looked back at him, Castiel knew somehow that Dean was plotting something. For good or for bad he wasn't sure – and he didn't particularly care either.

* * *

He was sitting in the park across the street from the church when he could feel the pull of a summoning reaching out to him. As discretely as possible, he rose to his feet and vanished before reappearing in the parking lot of a rundown motel somewhere along the Eastern Seaboard.

"Dean?"

Dean Winchester looked up from his makeshift altar and his eyes flashed from green to black.

"Cas," he said while smiling sincerely.

Castiel walked forward until he was in Dean's space, wrapped his arms around his neck and pulled him in for a rough, deep kiss. He had missed his Redeemer so much since they'd returned.

When they pulled away a few seconds later, Dean was pleased to see that, when Castiel looked up at him his eyes were totally white.

"Why have you summoned me here, Dean?" Castiel asked, his eyes slowly returning to normal and his face unusually flushed.

"I need your help with something big, Cas," Dean said, looking towards one of the doors of one of the rooms. "It involves Sam. You wanna help?"

Innocently, Castiel asked, "Will there be a reward should I respond positively?"

"Of course," Dean said after a moment before removing his small switchblade from his back pocket and pricking himself on the finger, drawing blood. Castiel watched entranced as Dean smeared the blood onto his own lips and leaned down to kiss the angel once again, wide and inviting.

When they pulled away from each other, Castiel wiped away the remaining blood from his lips and sucked on the finger until all of the red liquid was gone. He let out a breath of relief and Dean gave him another kiss, this one on the forehead.

"My answer is yes. Of course I will assist you with anything you desire, my Redeemer."

Dean let out a sigh of relief. "Awesome; thanks Cas. Okay so this is what I want you to do…"


	3. Moore

**Notes for the Chapter:**

> Disclaimer: I do not own Supernatural. This is being done for no monetary gain whatsoever.
> 
> Is this an update? Yes it is! I finally sat down and finished writing the third chapter for this.

A few days went by before Dean finally found something resembling a case. The one request that he made was that they call Castiel before going and Sam couldn't help but wonder why.

"I haven't even seen him since you got back," Sam said. "He's not, you know, too busy?"

"Yeah, he's probably doing heavenly, divine…stuff. It was all he'd talk about when we were stuck in Purgatory. So boring. It'll do him some good to, you know, learn how to hunt with us sometimes. Get the old team back together," Dean said while putting on his watch.

"Okay so what're we looking at this time?" Sam asked while tying his bootlace.

Leaning over the printout, Dean read aloud, "Four women in the general area of Moore, Oklahoma have all been killed in the last two weeks."

"Doesn't seem that weird."

Dean shoved the paper away and stood up. He grabbed his jacket and slipped it on. "They're being set on fire in empty apartments."

Before Sam could comment, Castiel finally appeared in the room in a flutter of furious wing beats looking the same as ever, right down to the tan trench coat.

"Hello, Sam," he said, just the same as always. The angel's eyes then drifted over to Dean and almost stiltedly he said in a strangely deeper than usual monotone, "Hello."

"So," Dean said, clapping his hands and grabbing his duffel, "ready to go?" He stood by Castiel and looked down at the angel beside him who had raised his hand to Dean's shoulder.

"Wait, aren't we taking the Impala?" Sam asked, confused. It wasn't like Dean to leave the car behind _at all._

"I will transport all of us there. The car too," Castiel said, removing his other hand from his pocket.

"See," Dean said, smiling a little too widely, "easy. No long car ride to annoy you."

"Dean, you love driving," Sam pointed out.

"Sam, let me explain something to you," Dean said, walking to his brother and putting his hands on his shoulders, gripping them tightly, "I just spent months running around in purgatory and trying not to die. Now, if there is a way for us to get somewhere and fast then I am going to take it. Capiche?"

Sam frowned but accepted the explanation. He wasn't in purgatory. Didn't have to run for his life or anything. It made sense.

* * *

Once they'd arrived on an empty road about twenty minutes from a motel, they drove the rest of the way in quiet. Dean hadn't even turned on the radio and Sam didn't pressure him to do so.

"Why don't you get the room for us," Dean said once they'd parked in the vacant motel lot.

"Okay," Sam said and walked to the main office.

After he'd filled out the necessary paperwork, he came back outside to find Dean putting his flask back into his pocket and Castiel wiping his mouth with the back of his hand.

"Which room?" Dean asked moving towards the trunk.

Sam continued staring at Castiel who most definitely was not staring back at him. The angel's eyes seemed to be faraway like he was seeing something far in the distance.

"Sam, which room?"

Sam looked down at the angel's wrist to see a blotch of red staining the white dress shirt –

"Sam!"

"What?" Sam asked, meeting eye to eye with his brother.

Dean smirked as if to prove everything was okay. "Which room are we in?"

Sam looked at the key in his hand and on the key chain was a handwritten number 13. "Room 13."

"Thirteen, my lucky number." Dean grabbed the key from his hand and went into the room.

Sam walked in just as Dean was throwing his duffel onto his chosen bed and then throwing himself onto it as well. "Dean, shouldn't we start working the case - research?"

"Right, you go do that," Dean said as he got comfortable. "I need to catch a few hours and -"

"Where'd Cas go?"

"What?"

Sam looked around the room and Castiel had already vanished before he had the chance to ask what he knew about this case. "Isn't Cas working the case with us?"

Dean laughed. "Of course. Dude's an angel. He's probably out looking for clues."

Dean continued to smile and Sam felt like he should be more worried than he felt.

"You want a drink?" Dean asked, taking out the flask, "You look like you need one."

"What?" Sam asked distractedly before shaking his head, "No. I'll be at the police station."

"Call me if you find anything," Dean said before dropping his head to the pillow again, shutting his eyes.

Quickly Sam changed into his best and only FBI suit and got into the Impala to search the city for the local police station.

* * *

"Cas," Dean said to the ceiling, "you can come back now. He's gone."

Dean leaned his head against the headboard and shut his eyes before hearing the telltale sound of wings by his side. The bed suddenly sunk down slightly and he turned and looked to see Castiel lying on his side beside him, his head propped up by his hand. Dean shifted himself to mirror his turned angel before running his free hand against said angel's face.

"You are so beautiful," he said and really meant it.

In the time since Sam and Dean had their little conversation, Castiel had changed from his "normal clothes" into something else. Instead of the suit and trench coat combo, now he was wearing a tight black V-neck long sleeved shirt with dark, snug jeans and strangely no shoes or socks, but just his bare feet which was something he was used to during their time in purgatory.

Castiel closed his eyes and sighed contentedly before saying, "Everything is coming together, Dean."

"Good," the former human said before pulling Castiel forward and kissing him.

Castiel reached out and pulled Dean's head closer to his, deepening the kiss.

"And…have I earned my reward?" the angel asked shyly.

"More than enough," Dean said.

He turned and grabbed his knife from the bedside table and both of them sat up, sitting cross legged on the bed. Dean ran the sharp end over his palm and once the blood welled up, turned it over to Castiel. Cas took the hand into both of his and, like a cat, lapped at the blood and allowed its chill to wash over him once again.

"Do you believe that if we ceased doing these activities, I would revert back to my former self?" Castiel asked once he was finished.

"No because I wouldn't allow it," Dean said willing his wound to heal.

Castiel made a pleased sounding noise before Dean reached out with his other hand to bring Castiel closer to him and he gave him a kiss on the top of the head. Once they broke apart, Castiel tentatively brought his hands to the hem of Dean's shirt. They locked eyes and Dean could practically feel the unbridled _need_ oozing off the angel in waves so he allowed his shirt to be removed. Castiel did it quickly and threw the shirt aside. The angel then ran a gentle hand against Dean's body, feeling the firm muscles beneath his fingertips. Dean took Castiel by the wrist and placed the fingertips against his lips, kissing them gently.

They always started off their times together like that – slow and sensual. Dean liked to take care of Castiel because the angel was the only one he could truly trust when they were trapped in that awful place between worlds.

He'd then molded him in his image as a reward and was more than pleased with the results.

* * *

Sam got back into the Impala and waited a minute before starting the car. His mind went back over the information he'd gained and something was just terribly...wrong.

Four girls were alone in their homes and suddenly fires would break out. Their names had been Jennifer, Elizabeth, Sarah and most recently Susan. None of the girls had any connections. What was the pattern? There was no doubt in Sam's mind that it was probably demons; this was seriously their mo. Unless it was some god or something else gathering sacrifices? Maybe Dean or Cas would have another idea.

Sam grabbed his cell and dialed his brother's number but it went right to voicemail.

"Dean, it's me. I'm on my way back. I'll bring lunch and we'll hash out what's going on. I dunno man, I think its demons or something. Later."

It wasn't like Dean to not answer. Maybe he was on the can.

* * *

Dean listened to the message playback.

"Well, I can say your brother is smart but we always knew that," Castiel commented from his place by Dean's side.

"It is demons. That's for sure," Dean said with a smirk.

Both men stood from the disheveled bed and watched each other as they put their clothes back on. Well, their pants at least.

"So," Dean asked, "do you have another girl all picked out?"

Castiel nodded. "I will be paying Irene a visit in a short while."

"Maybe my brother isn't that smart," Dean said. "I mean, he hasn't even noticed the pattern yet."

Castiel brushed his lips over Dean's and looked deeply into his blackened soul. "Irene and then Christina and then Amanda. Put the names together and they all spell out -"

"Jessica. Moore Oklahoma. Demons setting fire to girls whose names spell out Jessica," Dean said. "It's kinda genius."

"It was our little idea. Our 'pet project.'"

"Dude, you're getting better with those air quotes all the time."

Castiel smiled, pleased that he'd done right and kissed Dean once more before slowly pulling away. "Call for me when you need me. Anytime you need me."

Dean responded by licking his lips slowly and smirking. "See you later, Cas."

The angel bowed down his head to Dean and vanished.

Dean grabbed his shirt and put it back on before picking up his cell and dialing back Sam. "Hey Sam, got your message. Yeah, a burger would be great…."

**Notes for the Chapter:**

> This is so different than the other stories I'm working on. I love writing evil Dean and Castiel. Okay, I promise I won't make you guys wait so long for another chapter. Thanks very much for reading and let me know what you thought.


	4. Chill

**Notes for the Chapter:**

> Thank you to those of you reading this story. A Cas-centric chapter today. Sam and Dean should be back next time. Enjoy.

It had been a long, long day and Irene Kenner wanted nothing more than to fall into a warm bath and read the next chapter out of her latest book club novel. The meeting was at the end of the week and she'd barely gotten past chapter three.

"Excuse me?"

Irene turned and some dark haired, hot guy was running towards her. She looked up and down the street, wishing that someone else would show up so she wouldn't have to deal with it but she was unfortunately all on her own.

"Yeah?" she finally said.

Guy pointed down the road and said, "My automobile broke down and I am in need of a phone to dial my friend so he'll pick me up."

Oh for the love of –

"Just give me a minute," Irene groaned and finally managed to get the front door open.

She held it for the other guy who gave her a smile that kind of melted half of that giant ice chunk deep in her chest. They walked up two flights of stairs until they arrived at her apartment where she struggled with another door and opened it.

"Phone's right over there," she said gesturing vaguely to a far wall as she began to unpack her bags of groceries.

"Thank you," the guy said and picked up the receiver and dialed.

Her head was inside of the refrigerator when she heard him speak again.

"Hello, dear," he said. "Yes, I am on my way. Yes, I have found the right place. She was very helpful. I will deal with the situation and come back home in due time."

He hung up and Irene turned to have him right in her face. The guy tilted his head to the side and smiled a little too widely.

"Thank you for the use of your telephone."

"It's - it's no problem," she stuttered.

The guy began to advance on her and Irene had nowhere to go because her back was already against the fridge. He placed his hand against the pulse point of her right wrist and began to rub it slowly.

"You know, you are a beautiful woman, Irene. If I was interested in that sort of thing."

The breath couldn't leave Irene's lungs fast enough. He knew her name? How did he...How could he possibly...?

"How do you know me? Who are you?" she whispered.

"My name is Castiel," he said and Irene watched in bewilderment as his eyes rolled up in his head and the whites were the only thing showing.

He reached out his hand and grabbed her by the neck and began to squeeze.

* * *

_Purgatory -_

Castiel wrapped his arms around his body, trying to bring some measure of warmth to himself. In the days since they'd left the tiny cave, Castiel was beginning to sleep more and more and every time he'd awaken he'd feel more and more chilled. It was beginning to frighten him. In order to bring about their escape, Dean had given it one last mental push and the boulder simply evaporated into dust.

He'd celebrated by slaughtering a nest of vampires they came upon later that same day.

Almost a week later, he was now walking just slightly ahead of Castiel, humming something to himself. Dean was in a good mood so maybe it was best to not bring up his own worries. But still -

"Dean," he finally said after a moment's reflection, not being able to take it anymore, "may we please stop for a moment – I-I do not feel very well."

Dean looked at him and nodded. "Sure, buddy."

They stopped under a copse of trees and rocks and Castiel wrapped his coat tighter around himself but it wasn't really any use. He was still chilled. Dean looked at him worriedly for a minute before sitting next to him and putting a comforting arm around his shoulder.

"You okay, Cas? You're looking a little pale."

"I don't... I don't know what's wrong," Castiel stuttered. "It's just so cold..."

Dean opened his mouth to say something but closed it and began to rub small circles up and down Castiel's back. Castiel leaned his head against Dean's shoulder and dozed once more, unable to keep his eyes open.

* * *

It was sometime later that Castiel awoke, alone again, somehow inexplicitly feeling even more chilled than when he'd fallen asleep but also feeling beads of sweat against his brow. He heard shouting nearby and sat up to see two blurry people a short distance away. Where had Dean gone?

Castiel stood carefully on shaky legs and stalked closer to them, listening. Their voices came into and out of his ears as though he was hearing them from underwater. They were speaking a language too ancient for modern human ears but the angel understood what they were saying. They were a couple of skinwalkers, a male and a female. And they were talking about...a dark creature and his pet.

He knew that they were talking about Dean. About how there was some price on his head. How they needed him dead.

Anger welled up in Castiel. He needed to warn Dean, he needed to stop them...The skinwalkers began to choke and gasp.

The creatures looked around their immediate area but found nothing inhibiting their breathing. Castiel turned his head and watched as the male flew against a hard boulder (the same direction his head had turned), his back smacking the rock hard before collapsing to the forest floor. The woman meanwhile simply fell and Castiel walked towards her and tilted his head to the side as he drew closer.

"What's going on here?"

Castiel looked to see Dean coming towards him, holding some long sticks under his arms which he promptly threw to the ground.

"She and her mate were plotting your demise," Castiel said, his voice sounding strange to his own ears. Calm. Detached. Clinical.

"Were you?" Dean asked, leaning over the girl. The _bitch_.

Words that sounded like nonsense to Dean but clear as a bell to Castiel began pouring from her mouth in torrents.

"She is pleading for her life," Castiel said, his eyes trying to lock into Dean's.

"Ah," Dean said, his mouth stretching into a smirk, "is that what that is?"

She spat some more words and Dean had to hold Castiel back because he was about to attack her with his hands.

"Easy Cas. Calm down, man."

"She called you a spawn of the darkness," Castiel hissed through his teeth, pointing down at her.

"Well," Dean said reasonably, "Cas - that is kind of true."

Dean shifted his eyes to their black pools and Castiel sighed while rubbing his eyes, a headache building behind them. He felt that strange cold inching up his back again and bit back a shiver. Something strange was wrong with him.

"And it is all my fault. I could not keep you human and now I cannot do anything to make you change back."

"Hey, Cas - I told you, it's all right."

"It is not!" Castiel shouted back feverishly, "It's not!"

The woman screamed suddenly and Dean and Castiel turned to see her body burst into flames. They stepped away and when Castiel blinked, the fire burned out leaving only a scorch mark behind.

"What just happened?" Dean asked slowly.

"I believe," Castiel said carefully, "that I just destroyed the skinwalker woman's soul with my anger."

Dean turned and looked at him up and down, almost appraisingly. "You feeling okay, Cas?"

Castiel looked down at his hands and felt the chill thrumming throughout his body. He knew deep within himself that he had just somehow protected Dean for the first time since they'd arrived. It left him feeling…satisfied. Maybe the chill wasn't so bad after all. Slowly, the angel began to smile.

"I feel…fine."

* * *

The street was full of people and a little girl and her mother were walking by an older apartment building in Moore when the girl looked up to see something flickering in one of the rooms.

"Mommy, what's that?" she asked pointing upwards.

The mother indulged her child and looked before gasping.

"Oh my God - that's fire!" she shouted before reaching into her bag and pulling out her cell.

Other people on the street, having heard the woman yell, also stopped to look up. Everyone was doing the same, reaching for phones and dialing 911. The building was old – it could easily engulf the neighborhood if it burned for much longer.

"What has happened?" someone asked over her shoulder.

At that moment, a blast wave of fire shattered the single window, showering the ground below with shards of sharp glass. The mother turned to see a handsome, dark haired gentleman wearing a tan trenchcoat over a regular, tacky business suit.

"Can't you see?!" the woman said while pointing, "That apartment is on fire!"

"Ah, yes," the man said looking up, his eyes shining with misplaced mirth. "A shame. I hope there was no one inside."

"God," the woman said, looking up again, "I hadn't even thought of that."

"Well I suppose that if someone was inside," the man continued nonchalant, "she would have died quickly."

"How do you know it was a she?" Receiving no response, the mother turned to look him in the eye - but the man was gone. She looked around the gathering crowd but couldn't see anything resembling that tan coat.

"Mommy," the little girl asked, tugging on her mother's arm, "what's wrong?"

"Did you see that man; the one in the coat?" she asked her daughter.

"I blinked and he went away. Do you think he was an angel?"

"I don't know, baby," the mother said, kissing her daughter on the top of the head and pulled the girl closer to her side, feeling a strange chill in the air. "I don't know."


	5. Fever

**Notes for the Chapter:**

> Disclaimer: I do not own any part of the Supernatural franchise. This is being done purely for amusement.

Sam would've been blind to not notice his brother checking his phone every five seconds for the last twenty minutes. He put the newspaper that he was reading down on the rickety motel room table and sighed. His eyes were burning from over doing it, but they really needed to figure out what was going after these random girls and soon.

"Dean..." he began to say when the sound of a vibrating object interrupted him.

Dean grabbed his phone from his pocket, read something and smiled before putting it away. "What?" he asked while innocently looking up.

Motioning towards the phone with his chin, Sam asked, "What was that?"

"What was what?"

Sam pointed to his brother's pocket as he stood up from his uncomfortable seat. "That. Your phone? The one you've been obsessively looking at for the past half hour?"

"What? This?" Dean asked, pulling out the device.

"Someone send you a message?"

Dean grabbed his phone again and flipped it open. "Spam. You think I should get those pills for a bigger dick?"

Sam pulled a face. "Dean..." he groaned, making his brother chuckle.

"Relax; it was Cas. He's stopping by."

No sooner were the words out of his mouth when the angel himself appeared, standing dead center of the room.

"Cas," Dean said, jumping off of the bed, "you find anything?"

Castiel slowly turned to Dean and blinked once before shaking his head. "Whatever is afoot is hidden to me. Another girl has died this evening."

"Damn it," Sam exclaimed, throwing the paper he was studying to the floor.

"Anything else you can tell us?" Dean asked subtly. "A name maybe?"

"Irene Kenner. She burned alive in her apartment just twenty minutes ago."

While Sam retook his seat and wrote down the few notes they had, Castiel and Dean locked eyes and Dean mouthed two words to him –

"Good job."

* * *

_Purgatory -_

After they stopped to allow Castiel's strange fever to calm down, the two of them walked for three days straight before deciding to rest, hidden among some large boulders. The monsters had been avoiding them at large and only the stupid ones coming out of the woodwork attempted easily unnecessary attacks. Castiel's strange new powers also seemed to be weakening with the passing days. He claimed to start feeling warmth again though, as he said with some small amounts of irritation, "The chill was much nicer, especially in this climate. It also allowed me to better protect you should you be unable to protect yourself."

While they sat, Dean looked at Castiel and the angel looked back at him with an unsettled expression on his face. In Dean's eyes, Castiel appeared to be more harried than normal and it was quite possible his fever had returned. His eyes were glistening and his cheeks were rosy red.

"You're sure about that, Cas?" Dean asked, carefully looking down at his hands.

"Very."

Dean took out the hidden knife from his belt loop and Castiel watched as the demon deliberately cut himself on the back of the right hand, flinching at the bite of the pure silver knife. The sulfur-scented blood began to well up and after a second Dean raised his hand up willingly to his friend. Castiel realized after some thoughts and several deep inhalations what was required of him and he finally understood what Dean had been doing to him during his repeated stretches of total black outs. Castiel took the hand into both of his own, lowered his lips to the cut and began to lap up the liquid like a creature in dying need of sustenance. Dean leaned towards him and ran his free hand through Castiel's hair while the angel drank and then kissed him on the top of his shaggy, dirty head.

"It's okay, Cas," he whispered. "S'long as I'm around, you'll be okay."

Castiel's head rose at that and his lips were still stained with bright red blood when he leaned forward and kissed Dean with surprising fervor. After thinking that maybe it could've been just the fever, Dean melted into it and he leaned forward, forcing Castiel's back down to the mossy ground. When they broke apart to take a breath, Dean noticed that Cas' eyes had taken on a grayish tint, similar to that of a cataract.

"Are you positive you're okay with this, Cas? I can stop if you want me to. Right now. All you have to do is say, 'No'," Dean said carefully as he leaned his hand against his friend's flushed face.

Taking a moment to think it over, Castiel said while running his finger over the mark Dean made on himself, "Perhaps it is where we are now but, Dean, what I see that you are doing is ensuring that I myself can watch over you in a way that I have not been able to do for far too long. In the time that we have known each other, I had become yours and your brother's guardian and while that was not my initial mission, it happened and I do not regret what I have done. Well, some things, Crowley, but never to you. I also in time became your friend and, I now realize after much deliberation, that I felt deep within me that we could be so much more. Together. Brothers in arms, at an equal standing and not with you as a heavenly vessel. That was never your destiny and perhaps I was always meant to fall. Fall into the deepest depths of the darkness where I first caught a glimpse of your eternally beautiful soul."

Dean was utterly stunned by Cas' behavior and tone. "You don't...mind the demon blood I'm feeding you?" he asked.

Castiel, head ever so slightly tilted to the side, shook his head and again pulled Dean closer to himself and began to kiss him some more.

When they broke apart, Castiel whispered into Dean's ear, "Please, feed me again, my _love._ My _redeemer_."

Dean gave him one last, long look before he made a fresh cut, this time a small nick against his neck. Castiel leaned into him, putting his arms around Dean's shoulders and began to drink, his teeth forcing the cut to get ever so slightly larger and bleed just a tiny bit more. In his renewed fervor, he leaned so far into Dean's personal space that he was practically sitting on his lap.

"I will always stand with you, Dean," he whispered into his ear. "Always and forever for as long as we live."

Dean was beyond pleased with the result of his little experiment. If it worked like this on an angel, then perhaps… His mind roved away from where the two of them were seated, to beyond their trapped world where another potential soldier was lying in wait, ripe for the picking.

And that was when he started to plan his most brilliant and devious idea yet.

"Cas," he said pulling away. Reluctantly, his angel removed his mouth from his neck and this time the eyes that stared into his own were totally white.

"Yes, Dean?"

Dean flashed his own eyes to black and said while holding onto Castiel by the wrists tightly, "I think I've got an idea to how we can get out of here and what'll happen next."

* * *

Dean took one step towards the angel when -

"Wait."

Both Dean and Castiel looked over to Sam as he slowly stood, still clutching the notebook paper in his hands which had begun to shake ever so slightly.

"What's wrong, Sam?" Dean asked, remaining in place and crossing his arms.

"Ir - you said her name was Irene, Cas?"

"Yes."

"Irene with an 'I'?"

"Is there another way of spelling it that I am unaware of?"

"Irene. Irene..."

"You going anywhere with this, Sam?" Dean asked, getting annoyed. "What'd you find?"

Sam looked over to him and read off from his notes, "Jennifer, Elizabeth, Sara, Susan, Irene - Dean, their names, their _names_ , they're spelling..."

Dean shared a look with Castiel who appeared to be as unreadable as ever. It took months to read beyond that and know the angel was just about as excited as he was. This was it…

"Spelling, what?"

"Jes-Jessica."

He said the name as though after all of these years it still caused him no small amount of agony.

"Dean, the victims are spelling out Jessica's name with their first initials."

Sam's totally stricken expression almost undid Dean but he held forth. He walked to Sam and took the paper from his shaking hands as his brother ran off towards the bathroom and the sound of retching reached Dean's and Cas' ears.

Turning, Castiel whispered, suddenly unsure, "I can stop if you want me to."

Maybe this was too much. He knew that Dean hated hurting and his brother hurting was even worse. It was the master plan though. Sam needed to be broken first and then everything else would follow.

Dean licked his lips and shook his head. "No. Go to the next. Everything goes as planned, we'll be all-powerful. Team Free Will, right?"

Castiel looked unsure for another minute but he knew that Dean was right. He was always right. What they were doing _was right_.

Dean blinked and Castiel was gone to the next girl's home.

* * *

After fifteen long minutes, when he finally exited the bathroom, Sam immediately went to sit on his bed on the very edge and closed his eyes.

Jessica. Why did it have to be Jessica?

"Dean," he said clutching his hair in his hands tightly, "I think whatever this is, is something that's giving me some kind of message in particular."

He heard a beer bottle being opened and his brother's voice as he said, "Might be. Weird that they'd use Jess' name against you and bring you all the way out to a town called Moore."

Now Sam did open his eyes and they widened. "I hadn't even noticed that bit."

"Huh," Dean said, sitting next to him and handing his brother the bottle.

Sam drank it down, needing the distraction and smacked his lips upon finishing. Huh? Tasted a little strange. Must be a bad brew.

"Everything's going to be fine, Sammy. We'll see this thing through. Something's coming after you then we'll stop it. Together. Just you, me and Cas against the world. Nothing can stop Team Free Will, right?"

Dean reached over and pulled his brother into a tight, bear hug. His eyes flashed to black and Dean nodded against Sam's shoulder as he smirked.

"Everything is going to be just fine."


	6. Dosed

When Sam woke up very late the next morning, he was alone in their room and, after a minute's search, realized that Dean didn't even bother to leave him a note to say where he was going before he left.

Typical.

Sam got up and moved his tongue experimentally around in his mouth, still tasting that strange sour taste from the beer he drank before falling asleep. What a weird, weird brew. Sighing and still feeling tired, Sam went back to the table to continue his meager research.

What could they possibly do now? There were probably a ton of choices of girls in town - how would they know the right ones to protect? Technically there were only two letters left, the C and the A. Sam put his head into his hands and stared blankly down at his notes.

Who was going to be the C and the A?

* * *

The thunderstorm came out of nowhere and drenched Moore in rain and lightning. He was stood under the cover of a tree and he watched. He waited. The final two pieces of the puzzle were just out of reach, within his sights.

Dean Winchester breathed air into his nose and waited.

* * *

Sam didn't remember putting his head down or falling back to sleep but when a hand landed on his shoulder, he jumped up, spooked, and turned. It was only Cas.

"Sam," the angel said, removing his hand, "is everything all right?"

"Cas, um," Sam said, jumpy and pushing a strand of hair from his eyes, "what's up? You find anything?"

Cas looked at him through squinted eyes, studying him, but shook his head. Typical.

"Are you all right?" Cas asked again.

"I'm fine," Sam said exasperatedly. What was up with him today? He's never usually like this.

"You do not seem all right."

"I - I don't know. Anything your angel mojo can maybe fix?"

Cas give him a look over and laid a hand against his brow. Sam's eyes widened momentarily before he collapsed, asleep in his arms.

* * *

Two girls exited the sorority house at the same time, one holding the umbrella for both of them as they walked to their waiting car. The girls were twins, identical in looks right down to the beauty mark under their left eye. They were both blonde, in their twenties and had a huge poli-sci exam to get to that they'd both studied extremely hard for. The car that they got into was a 2011 Chevrolet Impala, black. A gift from their parents for graduation last spring. Christina Myers was behind the wheel while her sister Amanda sat in the passenger side seat. They put on their seatbelts, Christina turned the ignition and - the car exploded in an enormous fireball.

Dean smirked, closed his eyes and walked away. Time to begin part two.

* * *

There was something soft under his head that he did not remember being there before he'd lost consciousness. Wasn't he just sitting at the table? Sam hazily opened his eyes and the shadow of someone was leaning over him. He licked his lips and tasted something sweet and wet against them. It was something familiar, but what? The side of the bed sunk a little as someone sat down. Someone put a hand against his cheek and through hooded eyes Sam could've sworn it was Castiel.

"Cas?" he slurred.

"Shhh," Cas said, putting his finger to his lips and Sam did as asked. Cas put a hand against Sam's cheek and began to stroke him. "This is for the best," Cas said to him and, as Sam's vision began to improve, he could've sworn that there was something wrong with his face.

"What's for the best?"

"All of this, this was all Dean's idea," the angel continued. "Shortly after we'd arrived in Purgatory, I released a hold I had placed on him the very first time we met that allowed the darkness of his soul which was fine-tuned in hell to envelop the light within him. He became the demon that he once was, once again."

Sam tried to sit up but Cas firmly held him down.

"Perhaps it was still the after effects of my insanity but I thought I was doing the right thing. Dean was...was savage there. I tried to reign it in but I had no effect on him. He was changed - and then he decided to return the favor."

"What?" Sam said between a cough. "What're you talking about?"

"I was weak in that land, Sam," Cas said, looking him in the eye. "My grace was severely diminished and I could do nothing to assist Dean. And then I inexplicitly began to lose time, hours passing me by without my knowing what I was doing or what was happening around me..."

Cas brought his hands together and turned fully towards Sam.

"I began developing abilities, one by one as well as strange fevers that, instead of leaving me feeling warm, actually brought me to freezing cold."

Cas leaned right into Sam's face so Sam could see Cas' eyes. Instead of being their usual bright blue, they were cataract white and reminded him of Alistair. Of Lilith.

"I liked it, Sam. I liked the cold."

Cas got up off of the bed and began to pace while Sam sat up and brought himself to the edge, his feet against the floor. His head, oddly enough, was spinning.

"Did you, did you drug me?"

Cas stopped walking and raised his sleeve, revealing a fresh cut on his forearm.

"In a way..."

Sam, realizing what he'd been dosed with, got up to go into the bathroom and remove the taint from his body, but the door slammed shut before he could reach it. Turning back, Sam was met with Cas coming towards him.

"Dean came up with a plan after I agreed that he was doing the right thing for me. He said that, should we escape somehow from Purgatory and come back to the human world, we should not go after heaven nor hell but bring them to us."

"What does that even mean?" Sam, with his back against the bathroom door, jumped when Castiel suddenly smacked his hand against the door and stood before him, blocking any chance of him moving.

"We need you at full power Sam. It is the only way that we can achieve our goal."

"What goal?"

A third voice joined the conversation, saying, "World dominion."

Sam and Cas both turned to find Dean and Sam was more than shocked to see the wide smile appear on Cas' face. Cas moved away from blocking Sam, right into Dean's 'personal space bubble' and, calm as you please, pull his head down to his level and  _kiss him_. And Dean, what the hell, kissed him back.

They pulled each other away and turned back to Sam, one with black eyes and the other's white.

" _Exorcizamus te, omnis immundus spiritus..._ "

"Yeah, sorry Sammy," Dean said before raising his hand and Sam flew back against the bathroom door, "doesn't actually work when it's my own meatsuit."

"Dean, what the hell is wrong with you?" Sam asked though clenched teeth.

Dean smiled and stepped closer. "Nothing. For the first time in a very, very long time - I'm just fine." Dean then turned to Cas. "Did it work?" he asked.

Cas stood by his side and looked up to him, saying, "I have given him some of my blood and it appeared to be having an effect but he is going to need a lot more for it to have the full effect of what he once had."

Dean licked his lips and looked at Sam before looking to Cas again.

"It's out in the trunk."

Cas' eyes widened momentarily before he vanished from the room.

"Dean, you've gotta stop this. This isn't you."

Dean clenched his hand into a fist and Sam felt his airways closing up, as though he were being strangled. "No," he said, "this is exactly who I'm supposed to be."

Castiel reappeared holding three jugs of red, sulfur-scented liquid that he placed on the motel room table.

"Thanks Cas. You'll get your reward later."

Sam continued to struggle, trying to reach the good side of his brother. "Dean..."

"By the way," Dean said turning back to Sam, "Cas and me were the ones who were killing all those girls. Wanted to send you a little message."

Sam stopped trying to fight. "What - what kind of message?"

Dean smirked. "You can never escape your past, Sammy."

Sam suddenly felt a hand against his head and he lost consciousness once more.

**Notes for the Chapter:**

> I always know it's time to work on this story again when I start looking up demon Cas stories for fun. There's only going to be one more chapter after this one and it's finally finished. And, I'm warning you all now, there is not going to be a happy ending here. Sorry, this story doesn't work that way. Thanks for reading.


	7. Epilogue

**Notes for the Chapter:**

> Thank you for sticking with this story to the very end. If it wasn't for you readers, I probably would've abandoned the story a long time ago. I've said it before but I don't usually write stories like this. It was an experience, writing a piece like this and I don't regret it for a second.

_Months later –_

Peter looked carefully, _just_ over his shoulder and continued walking. That - that _girl_ had been following him for the last eight blocks.

She didn't look particularly imposing, whoever she was. She actually looked about a whole foot shorter than him and ten years younger. Barely even a high schooler. And were those blonde pigtails? Why wouldn’t she leave him alone? Why him?

She had a hand in the front pocket of her pink hooded sweatshirt where something looked like it was bulging. Oh no. Fuck, she's got a gun! She's going to rob him! Worse - she's going to kill him! She's some kind of serial killer and she's going to add his head to her tally!

But she looked like she was only fifteen years old. What is it with kids these days, huh?

Panicking at this point, Peter turned down the nearest alley and wasn’t really all that surprised at this point. None of the lights on any of the buildings was working save for one single weak bulb along the back wall above a door. He heard the soft sound of footsteps and the girl rounded the corner right behind him. In the pale light of the stars, he watched her draw from her pocketed sweatshirt a large, dangerous and very sharp looking kitchen knife.

She twirled it in her hand, raised it above her head and - a man jumped out of the shadows and stabbed something deep into her stomach. The girl lit up like a firework as she fell into the guy's arms and he lowered her down to the floor.

What the...? Was she tasered?

Two more people, both also male, appeared suddenly from the darkness. The first male removed the strange looking knife from the girl's stomach and stared at it.

"What, what happened?" Peter asked aloud.

The three men all turned to him as one and he realized his stupid mistake a second too late. The first one, the one with the knife, was the biggest of the three. He brought the blade to his mouth and...and... _licked_ the blade clean of blood. Like a child licking a good lollypop.

The shortest raised his hand and Peter found himself suddenly unable to move.

The third one laughed to himself and walked towards Peter until he was right up in his face. One second the man's eyes were a dark green and the next they were entirely black.

"You really, _really_ should've kept your mouth shut."

* * *

When they were finished, Cas was the one to check that the coast was clear before they could walk back out onto the main street without drawing any attention to themselves. Dean walked at the head of their little group. Castiel and Sam meanwhile walked just slightly behind him, flanking him on both sides. As they went past apartment buildings and storefronts, all of the demons that they passed within the general populace gave them wide, wide berth. Sam made a mental note of each one that they passed, letting his eyes flash a golden yellow before any of them had the chance to look away.

"Where to now, guys?" Dean asked suddenly.

"Maybe we should call it a night," Sam said with a sigh. "Make the call and plan for tomorrow."

One second the three of them were on the street, the next they were in their own little apartment just outside of downtown Detroit.

"All right Sammy," Dean said, putting his arm around Cas' shoulders, "You're on police call duty tonight and then, I don't know, do whatever it is that you do when me and Cas are -"

"Having loud, raucous sex in the next room?"

"Shut up, Bitch. But yeah."

Sam smirked at the two of them and raised his hands in surrender.

“Remember, _he_ stabbed _her_.”

“I know, Dean,” Sam said, pointing to his head. “I was there. Casual passerby.”

"Good night, Sam." Castiel walked away from Dean for a moment and gave Sam a kiss on the forehead and touched two of his fingers to his skull. Sam's eyes glazed over for a second before turning yellow and he grabbed his phone to report the crime.

Dean and Cas walked into their joint bedroom and shut and locked the door behind them.

"He doesn't try to fight you anymore," Dean commented while removing his shirt.

He turned to find Castiel already settling onto the bed, leaning on his side with one hand propping his head up and the other patting the space beside him. Dean settled in by his side and pulled Castiel to him, bringing their lips together for a sensual kiss. When they moved away from each other, Dean put his arm back behind his head and smiled as Castiel leaned his head against his side.

"Dean?"

Dean turned his head and gave Cas a kiss on the crown of his head. "Yeah?" he asked back.

"Are you content?"

That was an odd question from the former angel. "Why do you want to know?"

Cas snuggled in closer to Dean's body and sighed while running his finger against Dean's side, eliciting a surprising shiver. "Just wondering," he said back.

Dean adjusted himself so that he was looking Castiel straight in the eyes before putting his hand against the side of his face and smiling. "I'm…I’m better than fine," Dean said, his eyes switching from regular to demonic. Cas smirked and made his own eyes go white. The door to the room next door shut and locked and Dean smiled up at the ceiling.

"The three of us. Together. I don't think anything will ever try to go against us again."

Cas nodded his head against him. "It would be prudent for the monsters and the demons to hide whenever _we_ approach a town."

Dean sighed. “The Boy-king, the Protégé and the Fallen Angel. The more improved, better Team Free Will.”

Castiel made a purring sound of contentment. “Sleep well, my love.”

Dean gave his angel another kiss on the top of his head and thought back. Maybe everything had been leading up to this very moment. All of the choices that they’d made, everything they had done from the beginning and ending of the Apocalypse, to each of them going through hell and heaven and purgatory itself and back, was leading to right here and right now. Honestly, the world was going to go to shit in the end anyway so why not have a little fun. The world had no idea who was roaming around in it. The world had no idea.  


End file.
